A storm system currently centered over the mid-Mississippi Valley will drift northward.  Meanwhile, a slug of tropically enhanced moisture will ride northeastward along the storm’s trailing cold front, delivering as much as 1 to 3 inches of rain from the southeastern Plains into parts of the middle and lower Mississippi Valley.  By mid-week, showers will spread into portions of the eastern Great Lakes and Northeastern States.  Meanwhile, rain and snow showers will continue to spread inland across the Northwest. 

…